2016 SPRING FINAL Flashcards
1
Q
MAS is _____ proportional to pt. dose
A
Directly
2
Q
KVP is main controlling factor of __1__ but it also affects density mainly because it controls __2__.
A
- Contrast
2. Scatter
3
Q
Inverse Square Law:
If you double the distance, you cover __1__ the area with __2__ the intensity. If you cut distance in half, you cover __3__ the area with __4__ the intensity.
A
- 1/4
- 1/4
- 4x
- 4x
4
Q
30% rule deals with
A
MAS
5
Q
15% rule deals with
A
KVP
6
Q
30% rule states in order to make visible change in __1__ one must increase or decrease __2__ by 30%
A
- Density
2. MAS
7
Q
15% Rule: BELOW 90 kV 1. +10 kV=\_\_\_\_\_\_\_ 2. -10 kV=\_\_\_\_\_\_\_ ABOVE 90 kV 3. +15 kV=\_\_\_\_\_\_\_ 4. -15 kV=\_\_\_\_\_\_\_
A
- Cut mAs in 1/2
- Double mAs
- Cut mAs in 1/2
- Double mAs
8
Q
Increase OID=______ density
A
DECREASED (due to air gap and scatter bypassing IR)
9
Q
Increased screen speed= 1. MAS 2. Pt. Dose 3. Detail Decreased screen speed: 4. MAS 5. Pt. Dose 6. Detail
A
- Decrease
- Decrease
- Decrease
- Increase
- Increase
- Increase
10
Q
Increased collimation=_____ density
A
Decrease
11
Q
Decreased collimation=______ density
A
Increased
12
Q
As part density increases, IR density __1__. As part density decreases, IR density (RE) __2__.
A
- Decreases
2. Increases
13
Q
Degree of differences in density
A
Contrast
14
Q
High kV:
- _____ scale
- _____ contrast
- _____ colors
- _____ latitude
- _____ pt. dose
- _____ scatter
- ______ penetration
A
- Long
- Low
- Many
- Wide
- Decreased
- Increased
- More
15
Q
Low kV:
- ___scale
- ___ contrast
- ___ colors
- ___ latitude
- ___ pt. dose
- ___scatter
- ___ penetration
A
- Short
- High
- Few
- Narrow
- Increased
- Decreased
- Less
16
Q
Increased grid ratio= __1__ contrast ( __2__scatter)
A
- Increased
2. Less
17
Q
Decreased grid ratio=__1__ contrast ( __2__ scatter)
A
- Decreased
2. More
18
Q
Increased collimation=__1__ contrast.
Decreased collimaton=__2__ contrast
A
- Increased
2. Decreased
19
Q
Additive pathology requires what in technique?
A
Increase
20
Q
Destructive pathology requires what in technique?
A
Decrease
21
Q
3 geometric factors that control recorded detail:
1.
2.
3.
A
- Focal Spot (Small)
- OID (short)
- SID (long)
22
Q
As FS increases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
A
- Increases
2. Decreases
23
Q
As FS decreases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
A
- Decreases
2. Increases
24
Q
As SID increases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
A
- Decreases
2. Increases
25
As SID decreases, unsharpness (penumbra) __1__, recorded detail (umbra) __2__.
1. Increases
| 2. Decreases
26
As OID increases, unsharpness (penumbra) __1__, and recorded detail (umbra) __2__.
1. Increases
| 2. Decreases
27
As OID decreases, unsharpness (penumbra) __1__ and recorded detail (umbra) __2__.
1. Decreases
| 2. Increases
28
As IR/screen increases, detail __1__. A IR/screen decreases, detail __2__.
1. Decreases
| 2. Increases
29
Greatest enemy of detail:________
MOTION
30
Ways to overcome motion:
A.
B.
C.
A. Short exposure time
B. Clear instructions
C. Immobilization
31
Size distortion (__1__)=use short __2__ and long __3__ to overcome.
1. Magnification
2. OID
3. SID
32
Shape Distortion (__1__)=caused by __2__ of the tube, part, and IR. Two types: __3__ and __4__.
1. True distortion
2. Mal-alignment
3. Elongation
4. Foreshortening
33
Increased collimation:
1. ____ scatter
2. ____ density
3. ____ pt. dose
4. ____ contrast
1. Decreased
2. Decreased
3. Decreased
4. Increased
34
Decreased collimation:
1. ____ scatter
2. ____ density
3. ____ pt. dose
4. ____ contrast
1. Increased
2. Increased
3. Increased
4. Decreased
35
Piece of lead that is not a type of variable collimator.
Aperture diaphragm
36
Cones and cylinders form a _____ pattern on the IR.
Round
37
A variable collimator
Box-type
38
Automatic Collimator a.k.a __1__. Can only be used in the __2__.
1. PBL
| 2. Bucky
39
Example of organic grid interspacers
Cardboard and balsa wood
40
Example of inorganic interspacer
Aluminum
41
Do focusing grids have a required focusing distance?
Yes
42
If you use the SID outside of distance, you will get _____ cutoff.
Peripheral
43
If you use the grid upside down you will get __1__ which results in __2__ density on the edges on the image.
1. Complete peripheral grid cut off
| 2. Decreased
44
Do parallel/non-focused grid have a required focusing distance?
Nope
45
Can you angle with a Crossed/Cross-Hatch grid?
No!!!!
46
With a regular grid, never angle __1__ grid lines, only __2__ or __3__.
1. Across
2. Caudal
3. Cephalic
47
Portable and tabletop grids are __1__ whereas Bucky grids are __2__.
1. Stationary
| 2. Moving
48
The higher the grid ration, the more __1__ it is to use. If a part measures __2__ or more, use a grid.
1. Restrictive
| 2. 10 cm
49
Grid ratio=
| Formula
Height of Pb strips/Distance between Pb strips
50
Air-Gap technique uses increased __1__ to allow scatter to by pass the IR and act as a __2__.
6" air gap=__3__ grid
1. OID
2. Grid
3. 6:1
51
CR uses __1__. It as a phosphor layer made of Barium __2__ Crystals doped with __3__, called a __4__ phosphor where the latent image is formed.
1. IP
2. Flourohalide
3. Europium
4. Photostimulable
52
Exposed IP then put in image reader where a __1__ laser scans over PSP to release stored energy as __2__. A __3__ tube (PMT) collects light and converts in it into an __4__ and sends it to an __5__ for viewing.
1. Neon-helium
2. Visible light
3. Photomultiplier
4. Electronic signal
5. ADC
53
Then an intense __1__ is passed over PSP to remove and remaining __2__.
1. White light
| 2. Energy
54
Direct Digital Radiography (DR) uses __1__ that have a Thin-Film Transistor (TFT) layer divided into __2__.
1. Flat Panel Detectors
| 2. Detector Elements (DELs)
55
Indirect DR involves a 2 step process of converting X-ray first into __1__ then into __2__ during image acquisition. Typically made of __3__ or __4__.
1. Visible light
2. Electric charges
3. Cesium Iodide
4. Amorphous Silion (a-Si)
56
Direct DR uses ______ to convert exit radiation directly into electrical charges.
Amorphous Selenium (a-Se)
57
CR and DR have a much wider _______ than analog (film-screen) imaging.
Dynamic range
58
Increasing the _______ increases visibility of anatomical details.
Signal to Noise Ratio (SNR)
59
1. Film has emulsion on both sides
2. Used in this type of cassette
3. This case uses single emulsion film
1. Duplitized
2. Regular
3. Extremity
60
This is matching screen color to film sensitivity.
Spectral matching
61
Intensifying screen converts X-Ray into __1__.
| __2__ gives off blue light an __3__ gives of green light.
1. Light
2. Calcium Tungstate
3. Rare Earth
62
Emission of light from screen when stimulated by radiation
Luminescence
63
Is giving off light only while being exposed
Fluorescence
64
Is screen lag/glowing too long
Phosphorescence
65
```
Factors that affect screen speed
1.
2.
3.
4.
5.
6.
```
1. Phosphor size
2. Thickness of active layer
3. Type of phosphor
4. Reflective layer
5. Light absorbing layer
6. KVP
66
__1__ or __2__ graininess of image due to sat screen system. To control, increase mAs and __3__ kVp.
1. Quantum Mottle
2. Noise
3. Decrease
67
CR imaging plates uses __1__ Fluorohalide doped with __2__ as the photostimulable __3__.
1. Barium
2. Europium
3. Phosphor
68
DR=indirect conversion system uses __1__ iodide which relates light that interacts with __2__ to create electric charge. Direct conversion system uses __3__ to produce electric charge.
1. Cesium
2. Amorphous silicon (a-Si)
3. Amorphous selenium (a-Se)
69
Amount of darkness after processing.
Density
